Isolation and screening of yeast starters from ersho samples collected from different parts of Ethiopia and determination of their potential role for bread production

Abstract

Ersho, an undefined starter culture used for Ethiopian injera production, is well-known as a source of yeasts.However, there has not been negligible research done on the use of yeasts isolated from ersho samples for making bread.So, the present study was aimed at isolating and screening yeasts from ersho samples and evaluating their impact on the nutritional, microbial, and sensory quality of bread.A total of 55 ersho samples were collected from different locations in Ethiopia.An experimental research design was used.Three yeast isolates (4A, 14D, and 54A) were selected from a total of 220 yeast isolates.Yeast isolates 4A, 14D, 54A, 14D54A, and bakery yeast were used to make BY1, BY2, BY3, BY4, and control breads, respectively.Compared to other breads, BY4 exhibited superior qualities.Protein, TCC (total coliform count), TVC (total viable count), and TFC (total fungal count) of control bread were 13.56%, 0, 3.1, and 2.1 log cfu/g, respectively.Protein,TCC, TVC, and TFC of BY4 bread were 14.84%, 0, 2.4, and 1.6 log cfu/g, respectively.Color, texture, taste, odor, and overall acceptability mean scores of control bread were 6.6, 6.7, 6.9, 7.1, and 6.9, respectively, while those of BY4 bread were 6.8, 7.2, 7.2, 7.3, and 7.3, respectively.The shelf lives of the control and BY4 breads were 4 and 6 days, respectively.The results of the present study indicate that the wild yeasts isolated from the ersho samples can be used for the development of bakery yeast.